NON-PARAMETRIC MANN-KENDALL TEST FOR TREND DETECTION OF THE START AND END OF RAINY SEASON IN MEKONG DELTA

Abstract

This paper detects trend of the change of the beginning time and ending time of rainy season in Mekong delta usingnon-parametric Mann-Kendall test and Sen’s slope method.
The results show that the rainy season at Rach Gia and Ca Mau stations tended to be later: 5 days/decade and 4.4 days/decade, respectively while this number is about 2.7 days/decade at Vi Thanh station. The change of start of rainy season in other stations shows an unclear trend. The ending time of the rainy season tended to be later at Ba Tri station (about 8.5 days/decade) and Vinh Long (about 4.7 days/decade), whereas the ending time of the rainy season in Can Tho and Ca Mau stations tended to be sooner about 4.7 days/decade and 3.2 days/decade respectively.